why does CPUs/CPU cores seem to be capped at 3 – 4 Ghz since almost a decade?

Question

why does CPUs/CPU cores seem to be capped at 3 – 4 Ghz since almost a decade?

In: 1368

Answer 1

Simple: diminishing returns relative to power consumption.

Multiple cores at a lower frequency is more efficient than a single core at a higher frequency. Eventually processors came to sweet spot where the frequency and power dissipation were at a point where very little additional performance was gained.